We would drill deep to reach the marrow. Feldt helped me lay down the battery and align the bore. Seseq directed us, the coral's deep structures clear to her through some mechanism of the mirror in her face.

We had picked this bright stretch of coral for two reasons. Its arm thinned here, and so was easiest to mine. The second reason was Moth's passage - something we had, lightyears from here, scouring our charts cobbled together from traded data and our own amateur observatory findings, predicted - would provoke a curious excitement in the coral. From a distance its radiance had resembled Moth's. A cool pale thread. And far beneath its chaotic skin the marrow would also change.

I waved Feldt away. 'Stop crowding me,' I said, laying down the second clamp. A whir of screwdriver motion and oily dust and it was secure. Feldt stood in place, seemingly disoriented, then blinked. He drifted over to the opposite clamp. I shook my head.

Seseq barked a depth measurement. As I stood to configure the bore I thought I saw a figure moving out among the smoke-like structures. I sighed, my heart rate rising. 'Mark,' I said, jabbing the depth target into the machine.

'Already?'

Seseq sat quite far from us atop an outcropping of warped reefrock. She rose to her feet and looked at me, her face a division of reflected coral and void sky. The longer I looked at her the more the stars in her faceplate seemed to shimmer. I focused on the bore's interface.

'Just visual,' I said, batting away the mosquito buzzing in my ear, 'so far.'